491775091 has 2 divisors, whose sum is σ = 491775092. Its totient is φ = 491775090.

The previous prime is 491775071. The next prime is 491775131. The reversal of 491775091 is 190577194.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 491775091 - 2⁵ = 491775059 is a prime.

It is not a weakly prime, because it can be changed into another prime (491775061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245887545 + 245887546.

It is an arithmetic number, because the mean of its divisors is an integer number (245887546).

Almost surely, 2^491775091 is an apocalyptic number.

491775091 is a deficient number, since it is larger than the sum of its proper divisors (1).

491775091 is an equidigital number, since it uses as much as digits as its factorization.

491775091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 79380, while the sum is 43.

The square root of 491775091 is about 22176.0025928931. The cubic root of 491775091 is about 789.3243654575.

It can be divided in two parts, 4917 and 75091, that added together give a palindrome (80008).

The spelling of 491775091 in words is "four hundred ninety-one million, seven hundred seventy-five thousand, ninety-one".